U.S. patent application number 16/203790 was filed with the patent office on 2020-01-16 for semiconductor device including partially enlarged channel hole.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. The applicant listed for this patent is Samsung Electronics Co., Ltd.. Invention is credited to Eunyeoung CHOI, Junggeun Jee, Bio Kim, Hyung Joon Kim, Yujin Kim.
Application Number | 20200020713 16/203790 |
Document ID | / |
Family ID | 69139653 |
Filed Date | 2020-01-16 |
![](/patent/app/20200020713/US20200020713A1-20200116-D00000.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00001.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00002.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00003.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00004.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00005.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00006.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00007.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00008.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00009.png)
![](/patent/app/20200020713/US20200020713A1-20200116-D00010.png)
View All Diagrams
United States Patent
Application |
20200020713 |
Kind Code |
A1 |
CHOI; Eunyeoung ; et
al. |
January 16, 2020 |
SEMICONDUCTOR DEVICE INCLUDING PARTIALLY ENLARGED CHANNEL HOLE
Abstract
A semiconductor device includes a lower stack structure on a
substrate, an upper stack structure on the lower stack structure,
and a channel structure in a channel hole formed through the upper
stack structure and the lower stack structure. The channel hole
includes a lower channel hole in the lower stack structure, an
upper channel hole in the upper stack structure, and a partial
extension portion adjacent to an interface between the lower stack
structure and the upper stack structure. The partial extension
portion is in fluid communication with the lower channel hole and
the upper channel hole. A lateral width of the partial extension
portion may be greater than a lateral width of the upper channel
hole adjacent to the partial extension portion and greater than a
lateral width of the upper channel hole adjacent to the partial
extension portion.
Inventors: |
CHOI; Eunyeoung;
(Hwaseong-si, KR) ; Kim; Hyung Joon; (Hwaseong-si,
KR) ; Kim; Bio; (Hwaseong-si, KR) ; Kim;
Yujin; (Hwaseong-si, KR) ; Jee; Junggeun;
(Hwaseong-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electronics Co., Ltd. |
Suwon-si |
|
KR |
|
|
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
69139653 |
Appl. No.: |
16/203790 |
Filed: |
November 29, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 23/53295 20130101;
H01L 27/11582 20130101; H01L 27/1157 20130101 |
International
Class: |
H01L 27/11582 20060101
H01L027/11582; H01L 27/1157 20060101 H01L027/1157; H01L 23/532
20060101 H01L023/532 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 12, 2018 |
KR |
10-2018-0081134 |
Claims
1. A semiconductor device comprising: a substrate; a lower stack
structure on the substrate, the lower stack structure including a
plurality of lower insulating layers and a plurality of lower
conductive layers that are alternately stacked on the substrate; an
upper stack structure on the lower stack structure, the upper stack
structure including a plurality of upper insulating layers and a
plurality of upper conductive layers that are alternately stacked
on the lower stack structure, the upper stack structure and the
lower stack structure defining a channel hole that extends through
the upper stack structure and the lower stack structure, the
channel hole including a lower channel hole defined by the lower
stack structure, an upper channel hole defined by the upper stack
structure, and a partial extension portion adjacent to an interface
between the lower stack structure and the upper stack structure,
the partial extension portion being a portion of the channel hole
defined by an uppermost lower insulating layer and a lowermost
upper insulating layer among the plurality of lower insulating
layers and the plurality of upper insulating layers, the partial
extension portion being in fluid communication with the lower
channel hole and the upper channel hole, a lateral width of the
partial extension portion being greater than a lateral width of the
upper channel hole at a region adjacent to the partial extension
portion, and the lateral width of the partial extension portion
being greater than a lateral width of the lower channel hole at the
region adjacent to the partial extension portion; and a channel
structure in the channel hole.
2. The semiconductor device of claim 1, wherein an uppermost end of
the partial extension portion is at a higher level than the
interface.
3. The semiconductor device of claim 1, wherein a lowermost end of
the partial extension portion is at a lower level than the
interface.
4. The semiconductor device of claim 1, wherein the channel
structure includes a channel pattern; a tunnel insulating layer
surrounding an outside of the channel pattern; a charge storage
layer surrounding an outside of the tunnel insulating layer; a
lower blocking layer between the charge storage layer and the lower
stack structure; and an upper blocking layer between the charge
storage layer and the upper stack structure.
5. The semiconductor device of claim 4, wherein the upper blocking
layer is spaced to be apart from the lower blocking layer.
6. The semiconductor device of claim 4, wherein the charge storage
layer in the partial extension portion direct contacts the
lowermost upper insulating layer.
7. The semiconductor device of claim 4, wherein the charge storage
layer in the partial extension portion direct contacts the
uppermost lower insulating layer.
8. A semiconductor device comprising: a substrate; a lower stack
structure on the substrate, the lower stack structure including a
plurality of lower insulating layers and a plurality of lower
conductive layers that are alternately stacked on the substrate; an
upper stack structure on the lower stack structure, the upper stack
structure including a plurality of upper insulating layers and a
plurality of upper conductive layers that are alternately stacked
on the lower stack structure, the upper stack structure and the
lower stack structure defining a channel hole that extends through
the upper stack structure and the lower stack structure; and a
channel structure inside the channel hole, the channel structure
including, a channel pattern, a tunnel insulating layer surrounding
an outside of the channel pattern, a charge storage layer
surrounding an outside of the tunnel insulating layer, a lower
blocking layer between the charge storage layer and the lower stack
structure, and an upper blocking layer between the charge storage
layer and the upper stack structure, the upper blocking layer being
spaced to be apart from the lower blocking layer.
9. The semiconductor device of claim 8, wherein a lowermost end of
the upper blocking layer is at a higher level than an interface
between the lower stack structure and the upper stack
structure.
10. The semiconductor device of claim 8, wherein an uppermost end
of the lower blocking layer is at a lower level than an interface
between the lower stack structure and the upper stack
structure.
11. The semiconductor device of claim 8, wherein the charge storage
layer, between the upper blocking layer and the lower blocking
layer, directly contacts a lowermost layer of the plurality of
upper insulating layers.
12. The semiconductor device of claim 8, wherein the charge storage
layer, between the upper blocking layer and the lower blocking
layer, directly contacts an uppermost layer of the plurality of
lower insulating layers.
13. The semiconductor device of claim 8, further comprising: an
inner blocking layer surrounding an outside of the charge storage
layer, wherein the inner blocking layer is between the charge
storage layer and the lower stack structure, and the inner blocking
layer is between the charge storage layer and the upper stack
structure.
14. The semiconductor device of claim 13, wherein the inner
blocking layer, between the upper blocking layer and the lower
blocking layer, directly contacts a lowermost layer of the
plurality of upper insulating layers.
15. The semiconductor device of claim 14, wherein the inner
blocking layer extends between the lowermost layer of the plurality
of upper insulating layers and the charge storage layer.
16. The semiconductor device of claim 13, wherein the inner
blocking layer, between the upper blocking layer and the lower
blocking layer, contacts an uppermost layer of the plurality of
lower insulating layers.
17. The semiconductor device of claim 16, wherein the inner
blocking layer is between the uppermost layer of the plurality of
lower insulating layers and the charge storage layer.
18. The semiconductor device of claim 8, wherein the channel hole
includes a lower channel hole, an upper channel hole, and a partial
extension portion, the lower channel hole is defined by the lower
stack structure, the upper channel hole is defined by the upper
stack structure, the partial extension portion is adjacent to an
interface between the lower stack structure and the upper stack
structure, the partial extension portion is a portion of the
channel hole defined by an uppermost lower insulating layer and a
lowermost upper insulating layer among the plurality of lower
insulating layers and the plurality of upper insulating layers, the
partial extension portion is in fluid communication with the lower
channel hole and the upper channel hole, a lateral width of the
partial extension portion is greater than a lateral width of the
upper channel hole at a region adjacent to the partial extension
portion, and the lateral width of the partial extension portion is
greater than a lateral width of the lower channel hole at the
region adjacent to the partial extension portion.
19. A semiconductor device comprising: a substrate; a lower stack
structure on the substrate, the lower stack structure including a
plurality of lower insulating layers and a plurality of lower
conductive layers that are alternately stacked on the substrate; an
upper stack structure on the lower stack structure, the upper stack
structure including a plurality of upper insulating layers and a
plurality of upper conductive layers that are alternately stacked
on the lower stack structure, the upper stack structure and the
lower stack structure defining a channel hole that extends through
the upper stack structure and the lower stack structure, the
channel hole including a lower channel hole defined by the lower
stack structure, an upper channel hole defined by the upper stack
structure, and a partial extension portion adjacent to an interface
between the lower stack structure and the upper stack structure,
the partial extension portion being in fluid communication with the
lower channel hole and the upper channel hole, the partial
extension portion being a portion of the channel hole defined an
uppermost lower insulating layer and a lowermost upper insulating
layer among the plurality of lower insulating layers and the
plurality of upper insulating layer, a lateral width of the partial
extension portion being greater than a lateral width of the upper
channel hole at a region adjacent to the partial extension portion,
and the lateral width of the partial extension portion being
greater than a lateral width of the lower channel hole at the
region adjacent to the partial extension portion; and a channel
structure inside the channel hole, the channel structure including
a channel pattern, a tunnel insulating layer surrounding an outside
of the channel pattern, and an inner blocking layer, the charge
storage layer surround an outside of the tunnel insulating layer;
and the inner blocking layer surrounding an outside of the charge
storage layer.
20. The semiconductor device of claim 19, further comprising: a
lower blocking layer between the inner blocking layer and the lower
stack structure; and an upper blocking layer between the inner
blocking layer and the upper stack structure.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This U.S. non-provisional patent application claims priority
under 35 U.S.C. .sctn. 119 to and the benefit of Korean Patent
Application No. 10-2018-0081134, filed on Jul. 12, 2018, in the
Korean Intellectual Property Office (KIPO), the disclosure of which
is incorporated herein by reference in its entirety.
BACKGROUND
1. Field
[0002] Devices and methods consistent with example embodiments
relate to a multi-stack semiconductor device having a partially of
enlarged channel holes and a method of forming the multi-stack
semiconductor device.
2. Description of Related Art
[0003] Since semiconductor devices with greater integration density
are being developed, research has been conducted into a technique
of using a stack structure including a plurality of insulating
layers and a plurality of conductive layers that are alternately
stacked. A channel pattern may be formed through the stack
structure. A height of the stack structure is gradually on the
increase, and it is becoming increasingly difficult to uniformly
and continuously form the channel pattern.
SUMMARY
[0004] Example embodiments of inventive concepts are directed to
providing a semiconductor device having excellent electrical
properties and a method of forming the semiconductor device.
[0005] According to some example embodiments, a semiconductor
device may include a substrate, a lower stack structure on the
substrate, an upper stack structure on the lower stack structure,
and a channel structure. The lower stack structure may include a
plurality of lower insulating layers and a plurality of lower
conductive layers that are alternately stacked on the substrate.
The upper stack structure may include a plurality of upper
insulating layers and a plurality of upper conductive layers that
are alternately stacked on the lower stack structure. The upper
stack structure and the lower stack structure may define a channel
hole that extends through the upper stack structure and the lower
stack structure. The channel hole may include a lower channel hole
defined by the lower stack structure, an upper channel hole defined
by the upper stack structure, and a partial extension portion
adjacent to an interface between the lower stack structure and the
upper stack structure. The partial extension portion may be a
portion of the channel hole defined by an uppermost lower
insulating layer and a lowermost upper insulating layer among the
plurality of lower insulating layers and the plurality of upper
insulating layers. The partial extension portion may be in fluid
communication with the lower channel hole and the upper channel
hole. A lateral width of the partial extension portion may be
greater than a lateral width of the upper channel hole at a region
adjacent to the partial extension portion. The lateral width of the
partial extension portion may be greater than a lateral width of
the lower channel hole at the region adjacent to the partial
extension portion. The channel structure may be in the channel
hole.
[0006] According to some example embodiments, a semiconductor
device may include a substrate, a lower stack structure on the
substrate, an upper stack structure on the lower stack structure,
and a channel structure. The lower stack structure may include a
plurality of lower insulating layers and a plurality of lower
conductive layers that are alternately stacked on the substrate.
The upper stack structure may include a plurality of upper
insulating layers and a plurality of upper conductive layers that
are alternately stacked on the lower stack structure. The upper
stack structure and the lower stack structure may define a channel
hole that extends through the upper stack structure and the lower
stack structure. The channel structure may be in the channel hole.
The channel structure may include a channel pattern, a tunnel
insulating layer surrounding an outside if the channel pattern, a
charge storage layer surrounding an outside of the tunnel
insulating layer, a lower blocking layer between the charge storage
layer the lower stack structure, and upper blocking layer between
the charge storage layer and the upper stack structure. The upper
blocking layer may be spaced apart from the lower blocking
layer.
[0007] According to some example embodiments, a semiconductor
device may include a substrate, a lower stack structure on the
substrate, an upper stack structure on the lower stack structure,
and a channel structure. The lower stack structure may include a
plurality of lower insulating layers and a plurality of lower
conductive layers that are alternately stacked on the substrate.
The upper stack structure may include a plurality of upper
insulating layers and a plurality of upper conductive layers that
are alternately stacked on the lower stack structure. The upper
stack structure and the lower stack structure may define a channel
hole that extends through the upper stack structure and the lower
stack structure. The channel hole may include a lower channel hole
defined by the lower stack structure, an upper channel hole defined
by the upper stack structure, and a partial extension portion
adjacent to an interface between the lower stack structure and the
upper stack structure. The partial extension portion may be a
portion of the channel hole defined by an uppermost lower
insulating layer and a lowermost upper insulating layer among the
plurality of lower insulating layers and the plurality of upper
insulating layers. The partial extension portion may be in fluid
communication with the lower channel hole and the upper channel
hole. A lateral width of the partial extension portion may be
greater than a lateral width of the upper channel hole at a region
adjacent to the partial extension portion. The lateral width of the
partial extension portion may be greater than a lateral width of
the lower channel hole at the region adjacent to the partial
extension portion. The channel structure may be in the channel
hole. The channel structure includes a channel pattern, a tunnel
insulating layer surrounding an outside of the channel pattern, a
charge storage layer surrounding an outside of the tunnel
insulating layer, and an inner blocking layer surrounding an
outside of the charge storage layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view illustrating a
semiconductor device according to an example embodiment.
[0009] FIG. 2 is a detailed enlarged partial view of a portion of
FIG. 1.
[0010] FIG. 3 is a layout illustrating main components of the
semiconductor device according to an example embodiment.
[0011] FIGS. 4 to 6 are detailed enlarged partial views of a
portion of a semiconductor device according to example
embodiments.
[0012] FIG. 7 is a cross-sectional view illustrating a
semiconductor device according to an example embodiment.
[0013] FIGS. 8 to 10, 13, 16, 19, 22, 28, 31, 34, and 39 are
cross-sectional views taken along line I-I' of FIG. 3, illustrating
a method of forming a semiconductor device according to an example
embodiment.
[0014] FIGS. 11, 12, 14, 15, 17, 18, 20, 21, 23 to 27, 29, 30, 32,
33, and 35 to 38 are enlarged partial views illustrating a method
of forming a semiconductor device according to an example
embodiment.
DETAILED DESCRIPTION
[0015] FIG. 1 is a cross-sectional view illustrating a
semiconductor device according to an example embodiment. FIG. 2 is
a detailed enlarged partial view of a portion E1 of FIG. 1. FIG. 3
is a layout illustrating main components of the semiconductor
device. FIG. 1 is a cross-sectional view taken along line I-I' of
FIG. 3. A semiconductor device according to an example embodiment
may include a non-volatile memory, such as a vertical NAND (VNAND)
device or a three-dimensional (3D) flash memory.
[0016] Referring to FIG. 1, the semiconductor device according to
the example embodiment may include a substrate 21, a buried
conductive layer 25, a replacement conductive line 93, a support
50, a lower stack structure 60, an upper stack structure 160, a
plurality of channel holes 70H, a plurality of channel structures
70, a first interlayer insulating layer 89, an isolation trench 91,
an impurity region 94, insulating spacers 97, a trench buried layer
98, a second interlayer insulating layer 102, a plurality of
sub-bit plugs 103, a third interlayer insulating layer 104, a
plurality of sub-bit lines 105, a fourth interlayer insulating
layer 106, a bit plug 107, and a bit line 109.
[0017] The lower stack structure 60 may include a plurality of
lower insulating layers 61 and a plurality of lower conductive
layers 95, which are stacked alternately and repetitively. The
upper stack structure 160 may include a plurality of upper
insulating layers 161 and a plurality of upper conductive layers
195, which are stacked alternately and repetitively. A lowermost
layer of the plurality of lower conductive layers 95 may correspond
to a ground selection line GSL or a source selection line SSL. An
uppermost layer of the plurality of upper conductive layers 195 may
correspond to a string selection line SSL or a drain selection line
DSL. Some of the plurality of lower conductive layers 95 and the
plurality of upper conductive layers 195 may correspond to word
lines. The isolation trench 91 may correspond to a word line cut.
The replacement conductive line 93 may correspond to a common
source line CSL.
[0018] Each of the plurality of channel holes 70H may be formed
through (e.g., defined by) the upper stack structure 160, the lower
stack structure 60, the support 50, and the replacement conductive
line 93. Each of the plurality of channel holes 70H may include a
lower channel hole 71, an upper channel hole 171, and a partial
extension portion 171EH. The lower channel hole 71 may be disposed
in the lower stack structure 60. The upper channel hole 171 may be
disposed in the upper stack structure 160. The partial extension
portion 171EH may be adjacent to an interface S1 between the lower
stack structure 60 and the upper stack structure 160 and
communicate with the lower channel hole 71 and the upper channel
hole 171. The partial extension portion 171EH may be a portion of
the channel hole 70H defined by an uppermost lower insulating layer
and a lowermost upper insulating layer among the plurality of lower
insulating layers 61 and the plurality of upper insulating layers
161.
[0019] Each of the plurality of channel structures 70 may include
an information storage pattern 85, a channel pattern 86, a core
pattern 87, and a pad 88. The information storage pattern 85 may
include a lower blocking layer 72, an upper blocking layer 172, a
charge storage layer 82, and a tunnel insulating layer 83. The
plurality of channel structures 70 may be disposed inside the
plurality of channel holes 70H.
[0020] Referring to FIG. 2, a lateral width of the partial
extension portion 171EH may be greater than a lateral width of the
upper channel hole 171 adjacent to the partial extension portion
171EH. The lateral width of the partial extension portion 171EH may
be greater than a lateral width of the lower channel hole 71
adjacent to the partial extension portion 171EH.
[0021] An uppermost end of the partial extension portion 171EH may
be at a higher level than the interface S1 between the lower stack
structure 60 and the upper stack structure 160. A lowermost end of
the partial extension portion 171EH may be at a lower level than
the interface S1. The channel pattern 86 may surround the outside
of the core pattern 87. The tunnel insulating layer 83 may surround
the outside of the channel pattern 86. The charge storage layer 82
may surround the outside of the tunnel insulating layer 83. The
lower blocking layer 72 may be disposed between the charge storage
layer 82 and the lower stack structure 60. The upper blocking layer
172 may be disposed between the charge storage layer 82 and the
upper stack structure 160.
[0022] The upper blocking layer 172 may be spaced to be apart from
the lower blocking layer 72. A lowermost end of the upper blocking
layer 172 may be at a higher level than the interface S1. The
lowermost end of the upper blocking layer 172 may be at a lower
level than a lowermost layer of the plurality of upper conductive
layers 195. An uppermost end of the lower blocking layer 72 may be
at a lower level than the interface S1. The uppermost end of the
lower blocking layer 72 may be at a higher level than an uppermost
layer of the plurality of lower conductive layers 95. The charge
storage layer 82 may be in direct contact with a lowermost layer of
the plurality of upper insulating layers 161 between the upper
blocking layer 172 and the lower blocking layer 72. The charge
storage layer 82 may be in direct contact with an uppermost layer
of the plurality of lower insulating layers 61 between the upper
blocking layer 172 and the lower blocking layer 72.
[0023] The charge storage layer 82 in the partial extension portion
171EH may be in direct contact with the lowermost layer of the
plurality of upper insulating layers 161. The charge storage layer
82 in the partial extension portion 171EH may be in direct contact
with the uppermost layer of the plurality of lower insulating
layers 61. The charge storage layer 82 in the partial extension
portion 171EH may be in direct contact with the interface S1.
[0024] Referring to FIG. 3, stack structures 60 and 160, a
plurality of channel holes 70H, a plurality of isolation trenches
91, a plurality of bit lines 109, and a selection line isolation
pattern 112 may be disposed on a substrate 21. The stack structure
60 and 160 may include a lower stack structure 60 and an upper
stack structure 160.
[0025] FIGS. 4 to 6 are detailed enlarged partial views of a
portion of a semiconductor device according to example
embodiments.
[0026] Referring to FIG. 4, an information storage pattern 85 may
include a lower blocking layer 72, an upper blocking layer 172, an
inner blocking layer 272, a charge storage layer 82, and a tunnel
insulating layer 83.
[0027] The inner blocking layer 272 may surround the outside of the
charge storage layer 82. The inner blocking layer 272 may be
disposed between the charge storage layer 82 and the lower stack
structure 60 and between the charge storage layer 82 and the upper
stack structure 160. The inner blocking layer 272 may be in direct
contact with a lowermost layer of the plurality of upper insulating
layers 161 between the upper blocking layer 172 and the lower
blocking layer 72. The inner blocking layer 272 may be disposed
between the lowermost layer of the plurality of upper insulating
layers 161 and the charge storage layer 82. The inner blocking
layer 272 may be in direct contact with an uppermost layer of the
plurality of lower insulating layers 61 between the upper blocking
layer 172 and the lower blocking layer 72. The inner blocking layer
272 may be disposed between the uppermost layer of the plurality of
lower insulating layers 61 and the charge storage layer 82.
[0028] Referring to FIG. 5, an information storage pattern 85 may
include a lower blocking layer 72, an upper blocking layer 172, an
inner blocking layer 272, an outer blocking layer 372, a charge
storage layer 82, and a tunnel insulating layer 83.
[0029] The outer blocking layer 372 may cover top surfaces, bottom
surfaces, and side surfaces of a plurality of lower conductive
layers 95 and a plurality of upper conductive layers 195. The outer
blocking layer 372 may be disposed between the lower blocking layer
72 and the plurality of lower conductive layers 95 and between the
upper blocking layer 172 and the plurality of upper conductive
layers 195. The outer blocking layer 372 may include silicon oxide,
silicon nitride, silicon oxynitride, a high-k dielectric material,
or a combination thereof. The outer blocking layer 372 may include
the same material as the inner blocking layer 272, the upper
blocking layer 172, and the lower blocking layer 72. For example,
the outer blocking layer 372, the inner blocking layer 272, the
upper blocking layer 172, and the lower blocking layer 72 may
include silicon oxide.
[0030] In an embodiment, the outer blocking layer 372 may be
omitted. In an embodiment, the upper blocking layer 172 and the
lower blocking layer 72 may be omitted.
[0031] Referring to FIG. 6, a center of an upper channel hole 171
may be disposed to deviate from a center of a lower channel hole
71. An uppermost end of the lower blocking layer 72 may be at
substantially the same level as the interface S1. At least a
portion of a top surface of the lower blocking layer 72 may be at a
lower level than the interface S1.
[0032] FIG. 7 is a cross-sectional view illustrating a
semiconductor device according to an example embodiment.
[0033] Referring to FIG. 7, the semiconductor device according to
the example embodiment may include a substrate 21, a device
isolation layer 213, a plurality of transistors 215, a lower
interlayer insulating layer 217, a peripheral circuit
interconnecting wire 219, a buried conductive layer 25, a
replacement conductive line 93, a support 50, a lower stack
structure 60, an upper stack structure 160, a plurality of lower
channel holes 71, a plurality of upper channel holes 171, a partial
extension portion 171EH, a plurality of channel structures 70, a
first interlayer insulating layer 89, an isolation trench 91, an
impurity region 94, insulating spacers 97, a trench buried layer
98, a second interlayer insulating layer 102, a plurality of
sub-bit plugs 103, a third interlayer insulating layer 104, a
plurality of sub-bit lines 105, a fourth interlayer insulating
layer 106, a bit plug 107, and a bit line 109. The semiconductor
device according to the example embodiment may be interpreted as
including a cell-on-peripheral (COP) structure.
[0034] In an embodiment, the device isolation layer 213 may include
silicon oxide, silicon nitride, silicon oxynitride, a low-k
dielectric material, or a combination thereof. The plurality of
transistors 215 may include a fin field-effect transistor (finFET),
a multi-bridge channel (MBC) transistor, a nanowire transistor, a
vertical transistor, a recess-channel transistor, three-dimensional
(3D) transistor, a planar transistor, or a combination thereof. The
lower interlayer insulating layer 217 may include silicon oxide,
silicon nitride, silicon oxynitride, a low-k dielectric material,
or a combination thereof. The peripheral circuit interconnecting
wire 219 may include a metal, a metal nitride, a metal silicide,
polysilicon (poly-Si), conductive carbon, or a combination thereof.
The lower conductive layer 25 may include a plurality of
semiconductor layers having different conductivity types, a metal
layer, a metal nitride layer, a metal silicide layer, a conductive
carbon layer, or a combination thereof. The plurality of
transistors 215 and the peripheral circuit interconnecting wire 219
may constitute a peripheral circuit in various combinations.
[0035] FIGS. 8 to 10, 13, 16, 19, 22, 28, 31, 34, and 39 are
cross-sectional views taken along line I-I' of FIG. 3, illustrating
a method of forming a semiconductor device according to an example
embodiment. FIGS. 11, 12, 14, 15, 17, 18, 20, 21, 23 to 27, 29, 30,
32, 33, and 35 to 38 are enlarged partial views illustrating a
method of forming the semiconductor device.
[0036] Referring to FIGS. 3 and 8, a buried conductive layer 25 may
be defined in a desired (and/or alternatively predetermined) region
of a substrate 21. A mold layer 29 may be formed on the buried
conductive layer 25. The mold layer 29 may include a lower mold
layer 29A, a middle mold layer 29M, and an upper mold layer 29C,
which are sequentially stacked. A support 50 may be formed on the
mold layer 29. A preliminary lower stack structure 60T may be
formed on the support 50 by alternately and repetitively stacking a
plurality of lower insulating layers 61 and a plurality of lower
sacrificial layers 62.
[0037] The substrate 21 may include a semiconductor substrate, such
as a silicon wafer or a silicon on insulator (SOI) wafer. For
example, the substrate 21 may be a P-type single-crystalline
silicon wafer. The buried conductive layer 25 may be formed to have
a desired (and/or alternatively predetermined) depth from a surface
of the substrate 21. The buried conductive layer 25 may be a P type
or an N type. For instance, the buried conductive layer 25 may
include N-type single-crystalline silicon. In an embodiment, the
buried conductive layer 25 may include a semiconductor layer, such
as poly-Si. The buried conductive layer 25 may be omitted.
[0038] The mold layer 29 may include an oxide, a nitride, a
semiconductor, or a combination thereof. The mold layer 29 may
include a material having an etch selectivity with respect to the
buried conductive layer 25. The middle mold layer 29M may include a
material having an etch selectivity with respect to the buried
conductive layer 25), the lower mold layer 29A, and the upper mold
layer 29C. For example, the lower mold layer 29A may include
silicon oxide, the middle mold layer 29M may include silicon
nitride, and the upper mold layer 29C may include silicon oxide. A
thickness of the middle mold layer 29M may be greater than that of
the lower mold layer 29A or that of the upper mold layer 29C. The
support 50 may cover the mold layer 29. The support 50 may include
a material having an etch selectivity with respect to the mold
layer 29. For example, the support 50 may include poly-Si.
[0039] The plurality of lower insulating layers 61 may include an
insulating material, such as silicon oxide, silicon nitride,
silicon oxynitride, or a combination thereof. The plurality of
lower sacrificial layers 62 may include a material having an etch
selectivity with respect to the plurality of lower insulating
layers 61. For example, the plurality of lower insulating layers 61
may include an oxide, such as silicon oxide, and the plurality of
lower sacrificial layers 62 may include a nitride, such as silicon
nitride. A lowermost layer of the preliminary lower stack structure
60T may be a lowermost layer of the plurality of lower insulating
layers 61, and an uppermost layer of the preliminary lower stack
structure 60T may be an uppermost layer of the plurality of lower
insulating layers 61.
[0040] Referring to FIGS. 3 and 9, a plurality of lower channel
holes 71 may be formed through the preliminary lower stack
structure 60T, the support 50, and the mold layer 29 using a
patterning process. Each of the plurality of lower channel holes 71
may be completely formed through the preliminary lower stack
structure 60T, the support 50, and the mold layer 29 and penetrate
into the buried conductive layer 25. A lower blocking layer 72, a
lower sacrificial liner 73, and a lower sacrificial buried layer 74
may be formed inside the plurality of lower channel holes 71.
[0041] The lower blocking layer 72 may include silicon oxide,
silicon nitride, silicon oxynitride, a high-k dielectric material,
or a combination thereof. For example, the lower blocking layer 72
may include silicon oxide. The lower sacrificial liner 73 may
include a material having an etch selectivity with respect to the
lower blocking layer 72 and the lower sacrificial buried layer 74.
The lower sacrificial liner 73 may include silicon oxide, silicon
nitride, silicon oxynitride, a high-k dielectric material, or a
combination thereof. For example, the lower sacrificial liner 73
may include silicon nitride. The lower sacrificial buried layer 74
may include a material having an etch selectivity with respect to
the lower sacrificial liner 73. The lower sacrificial buried layer
74 may include poly-Si, silicon oxide, silicon nitride, silicon
oxynitride, or a combination thereof. For instance, the lower
sacrificial buried layer 74 may include poly-Si.
[0042] The formation of the lower blocking layer 72, the lower
sacrificial liner 73, and the lower sacrificial buried layer 74 may
include a plurality of thin-film forming processes and a plurality
of planarization processes. The plurality of planarization
processes may include a chemical mechanical polishing (CMP)
process, an etchback process, or a combination thereof. The lower
sacrificial liner 73 may surround side surfaces and a bottom
surface of the lower sacrificial buried layer 74. The lower
blocking layer 72 may surround outer side surfaces and a bottom
surface of the lower sacrificial liner 73. The lower blocking layer
72 may be in direct contact with inner walls of the plurality of
lower channel holes 71. The lower blocking layer 72 may be in
direct contact with the plurality of lower insulating layers 61,
the plurality of lower sacrificial layers 62, the support 50, the
mold layer 29, and the buried conductive layer 25.
[0043] Referring to FIGS. 3 and 10, a preliminary upper stack
structure 160T may be formed by alternately and repetitively
stacking a plurality of upper insulating layers 161 and a plurality
of upper sacrificial layers 162 on the preliminary lower stack
structure 60T. An interface S1 may be formed between the
preliminary lower stack structure 60T and the preliminary upper
stack structure 160T. A mask pattern 169 may be formed on the
preliminary upper stack structure 160T. A plurality of upper
channel holes 171 may be formed through the preliminary upper stack
structure 160T using a patterning process.
[0044] The plurality of upper insulating layers 161 may include an
insulating material, such as silicon oxide, silicon nitride,
silicon oxynitride, or a combination thereof. The plurality of
upper insulating layers 161 may include substantially the same
material as the plurality of lower insulating layers 61. The
plurality of upper sacrificial layers 162 may include a material
having an etch selectivity with respect to the plurality of upper
insulating layers 161. The plurality of upper sacrificial layers
162 may include substantially the same material as the plurality of
lower sacrificial layers 62. For example, the plurality of upper
insulating layers 161 may include an oxide, such as silicon oxide,
and the plurality of upper sacrificial layers 162 may include a
nitride, such as silicon nitride.
[0045] A lowermost layer of the preliminary upper stack structure
160T may be a lowermost layer of the plurality of upper insulating
layers 161, and an uppermost layer of the preliminary upper stack
structure 160T may be an uppermost layer of the plurality of upper
insulating layers 161. The lowermost layer of the plurality of
upper insulating layers 161 may be in direct contact with the
uppermost layer of the plurality of lower insulating layers 61. The
interface S1 may be formed between the uppermost layer of the
plurality of lower insulating layers 61 and the lowermost layer of
the plurality of upper insulating layers 161. Each of the plurality
of upper channel holes 171 may have a bottom surface formed at a
lower level than the interface S1.
[0046] FIGS. 11 and 12 are detailed enlarged partial views of a
portion E1 of FIG. 10. Referring to FIG. 11, a center of an upper
channel hole 171 may be vertically aligned with a center of a lower
channel hole 71. The lower sacrificial buried layer 74 may be
exposed at the bottom surface of the upper channel hole 171. The
bottom surface of the upper channel hole 171 may be at a lower
level than an upper end of the lower sacrificial buried layer
74.
[0047] Referring to FIG. 12, the center of the upper channel hole
171 may deviate from the center of the lower channel hole 71. The
lower sacrificial buried layer 74, the lower sacrificial liner 73,
and the lower blocking layer 72 may be exposed at the bottom
surface of the upper channel hole 171.
[0048] FIGS. 14 and 15 are detailed enlarged partial views of a
portion E1 of FIG. 13. Referring to FIGS. 3, 13, and 14, an upper
blocking layer 172, an upper sacrificial liner 173, and an upper
channel sacrificial layer 174 may be formed inside the plurality of
upper channel holes 171. A lower end of the upper blocking layer
172 may be at a lower level than an uppermost end of the lower
blocking layer 72.
[0049] The upper blocking layer 172 may substantially conformally
cover sidewalls and bottom surfaces of the plurality of upper
channel holes 171. The upper blocking layer 172 may include silicon
oxide, silicon nitride, silicon oxynitride, high-k dielectric
material, or a combination thereof. The upper blocking layer 172
may include the same material as the lower blocking layer 72. For
example, the lower blocking layer 72 and the upper blocking layer
172 may include silicon oxide.
[0050] The upper sacrificial liner 173 may substantially
conformally cover a surface of the upper blocking layer 172. The
upper sacrificial liner 173 may include a material having an etch
selectivity with respect to the upper blocking layer 172 and the
upper channel sacrificial layer 174. The upper sacrificial liner
173 may include silicon oxide, silicon nitride, silicon oxynitride,
a high-k dielectric material, or a combination thereof. The upper
sacrificial liner 173 may include the same material as the lower
sacrificial liner 73. For example, the lower sacrificial liner 73
and the upper sacrificial liner 173 may include silicon
nitride.
[0051] The upper channel sacrificial layer 174 may substantially
conformally cover a surface of the upper sacrificial liner 173. The
upper channel sacrificial layer 174 may include a material having
an etch selectivity with respect to the upper sacrificial liner
173. The upper channel sacrificial layer 174 may include poly-Si,
silicon oxide, silicon nitride, silicon oxynitride, or a
combination thereof. The upper channel sacrificial layer 174 may
include the same material as the lower sacrificial buried layer 74.
For example, the lower sacrificial buried layer 74 and the upper
channel sacrificial layer 174 may include poly-Si.
[0052] Referring to FIG. 15, the upper blocking layer 172 may be in
direct contact with the lower blocking layer 72 and the lower
sacrificial liner 73.
[0053] FIGS. 17 and 18 are detailed enlarged partial views of a
portion E1 of FIG. 16. Referring to FIGS. 3, 16, 17, and 18, the
lower sacrificial buried layer 74 may be exposed at bottom surfaces
of the plurality of upper channel holes 171 using an anisotropic
etching process. The upper blocking layer 172 and the upper
sacrificial liner 173 may be exposed at sidewalls of the plurality
of upper channel holes 171. The upper channel sacrificial layer 174
may remain on the sidewalls of the plurality of upper channel holes
171.
[0054] FIGS. 20 and 21 are detailed enlarged partial views of a
portion E1 of FIG. 19. Referring to FIGS. 3, 19, 20, and 21, the
upper sacrificial liner 173 exposed at the sidewalls of the
plurality of upper channel holes 171 may be partially removed using
an isotropic etching process to form a plurality of first gap
regions 173G. The upper blocking layer 172 may be partially exposed
by the plurality of first gap regions 173G. Uppermost ends of the
plurality of first gap regions 173G may be at a higher level than
the interface S1 between the preliminary lower stack structure 60T
and the preliminary upper stack structure 160T.
[0055] Referring to FIGS. 3 and 22, the upper blocking layer 172
may be partially removed using an isotropic etching process to form
a partial extension portion 171EH.
[0056] FIGS. 23 and 24 are detailed enlarged partial views of a
portion E1 of FIG. 22. Referring to FIG. 23, an uppermost end of
the partial extension portion 171EH may be at a higher level than
the interface S1 between the preliminary lower stack structure 60T
and the preliminary upper stack structure 160T. A lowermost end of
the upper blocking layer 172 may remain at a higher level than the
interface S1.
[0057] During the partial removal of the upper blocking layer 172,
a lowermost layer of the plurality of upper insulating layers 161,
an uppermost layer of the plurality of lower insulating layers 61,
and the lower blocking layer 72 may be partially removed. A lateral
width of the partial extension portion 171EH may be greater than a
lateral width of the upper channel hole 171 adjacent to the partial
extension portion 171EH and may be greater than a lateral width of
the lower channel hole 71 adjacent to the partial extension portion
171EH. A lowermost end of the partial extension portion 171EH may
be at a lower level than the interface S1. An uppermost end of the
lower blocking layer 72 may remain at a lower level than the
interface S1.
[0058] Referring to FIG. 24, the uppermost end of the lower
blocking layer 72 may remain at substantially the same level as the
interface S1. A portion of a top surface of the lower blocking
layer 72 may be at a lower level than the interface S1.
[0059] FIGS. 25 to 27 are enlarged partial views illustrating a
method of forming the semiconductor device. Referring to FIG. 25,
in an embodiment, a lower sacrificial buried layer 74 may be
exposed at a bottom surface of an upper channel hole 171, and a
surface oxide layer 1740 may be formed in an upper channel
sacrificial layer 174 and the lower sacrificial buried layer 74.
The formation of the surface oxide layer 1740 may include a thermal
oxidation method, a plasma oxidation method, or a combination
thereof.
[0060] Referring to FIG. 26, an upper sacrificial liner 173 exposed
at a sidewall of the upper channel hole 171 may be partially
removed to form a first gap region 173G.
[0061] Referring to FIG. 27, an upper blocking layer 172 may be
partially removed using an isotropic etching process to form a
partial extension portion 171EH. The surface oxide layer 1740 may
be removed during the removal of the upper blocking layer 172.
[0062] FIGS. 29 and 30 are detailed enlarged partial views of a
portion E1 of FIG. 28. Referring to FIGS. 3, 28, 29, and 30, the
upper channel sacrificial layer 174 and the lower sacrificial
buried layer 74 may be removed using an isotropic etching
process.
[0063] Referring to FIGS. 3 and 31, the upper sacrificial liner 173
and the lower sacrificial liner 73 may be removed using an
isotropic etching process. The lower channel hole 71, the partial
extension portion 171EH, and the upper channel hole 171 may
constitute a channel hole 70H. In an embodiment, after the upper
sacrificial liner 173 and the lower sacrificial liner 73 are
removed, a recovery process, such as a thermal oxidation process, a
plasma oxidation process, a cleaning oxidation process, or a
combination thereof, may be performed to recover etching damages of
the lower blocking layer 72 and the upper blocking layer 172.
[0064] FIGS. 32 and 33 are detailed enlarged partial views of a
portion E1 of FIG. 31. Referring to FIG. 32, the partial extension
portion 171EH may be formed adjacent to the interface S1. An
uppermost layer of the plurality of lower insulating layers 61 and
a lowermost layer of the plurality of upper insulating layers 161
may be partially exposed in the partial extension portion 171EH.
The partial extension portion 171EH may communicate between the
lower channel hole 71 and the upper channel hole 171. The lower
blocking layer 72 may remain on a sidewall of the lower channel
hole 71. An uppermost end of the lower blocking layer 72 may remain
at a lower level than the interface S1. The upper blocking layer
172 may remain on a sidewall of the upper channel hole 171. A
lowermost end of the upper blocking layer 172 may remain at a
higher level than the interface S1.
[0065] Referring to FIG. 33, a center of the upper channel hole 171
may be formed to deviate from a center of the lower channel hole
71. The partial extension portion 171EH may communicate between the
lower channel hole 71 and the upper channel hole 171. The uppermost
end of the lower blocking layer 72 may remain at substantially the
same level as the interface S1. A portion of a top surface of the
lower blocking layer 72 may be formed at a lower level than the
interface S1.
[0066] FIGS. 35 to 38 are detailed enlarged partial views of a
portion E1 of FIG. 34. Referring to FIGS. 3, 34, 35, and 36, a
charge storage layer 82, a tunnel insulating layer 83, a channel
pattern 86, and a core pattern 87 may be formed inside the channel
hole 70H using a plurality of thin-film forming processes and a
plurality of planarization processes. The mask pattern 169 may be
removed. The lower blocking layer 72, the upper blocking layer 172,
the charge storage layer 82, and the tunnel insulating layer 83 may
constitute an information storage pattern 85.
[0067] The core pattern 87 may fill the inside of the channel hole
70H. The channel pattern 86 may surround a bottom surface and side
surfaces of the core pattern 87. The tunnel insulating layer 83 may
surround a bottom surface and outer side surfaces of the channel
pattern 86. The charge storage layer 82 may surround a bottom
surface and outer side surfaces of the tunnel insulating layer 83.
The charge storage layer 82 may be formed between the lower
blocking layer 72 and the tunnel insulating layer 83 and between
the upper blocking layer 172 and the tunnel insulating layer 83. In
the partial extension portion 171EH, the charge storage layer 82
may be in direct contact with an uppermost layer of the plurality
of lower insulating layers 61 and a lowermost layer of the
plurality of upper insulating layers 161.
[0068] The charge storage layer 82 may include silicon nitride. The
tunnel insulating layer 83 may include silicon oxide. The channel
pattern 86 may include a semiconductor layer, such as poly-Si. For
example, the channel pattern 86 may include a P-type poly-Si layer.
The core pattern 87 may include an insulating layer, such as
silicon oxide, silicon nitride, silicon oxynitride, or a
combination thereof. In an embodiment, the core pattern 87 may be
omitted. The channel pattern 86 may fill the insides of the
plurality of lower channel holes 71, the partial extension portion
171EH, and the plurality of upper channel holes 171.
[0069] Referring to FIG. 37, in an embodiment, before the charge
storage layer 82 is formed, an inner blocking layer 272 may be
formed. The inner blocking layer 272 may substantially conformally
cover a sidewall and a bottom surface of the channel hole 70H. The
inner blocking layer 272 may cover side surfaces of the lower
blocking layer 72 and the upper blocking layer 172. In the partial
extension portion 171EH, the inner blocking layer 272 may be in
direct contact with the uppermost layer of the plurality of lower
insulating layers 61 and the lowermost layer of the plurality of
upper insulating layers 161. The inner blocking layer 272 may
include silicon oxide, silicon nitride, silicon oxynitride, a
high-k dielectric material, or a combination thereof. The inner
blocking layer 272 may include the same material as the upper
blocking layer 172 and the lower blocking layer 72. For example,
the inner blocking layer 272, the upper blocking layer 172, and the
lower blocking layer 72 may include silicon oxide.
[0070] In an embodiment, before the inner blocking layer 272 is
formed, the upper blocking layer 172 and the lower blocking layer
72 may be omitted.
[0071] Referring to FIG. 38, a charge storage layer 82, a tunnel
insulating layer 83, a channel pattern 86, and a core pattern 87
may be sequentially formed on the inner blocking layer 272. The
charge storage layer 82 may substantially conformally cover the
inner blocking layer 272. The tunnel insulating layer 83 may
substantially conformally cover the charge storage layer 82. The
channel pattern 86 may substantially conformally cover the tunnel
insulating layer 83.
[0072] Referring back to FIGS. 10 to 38, a method of forming a
semiconductor device according to an example embodiment may include
partially removing the upper blocking layer 172. A lowermost end of
the upper blocking layer 172 may be formed at a higher level than
the interface S1 between the preliminary lower stack structure 60T
and the preliminary upper stack structure 160T. The upper blocking
layer 172 may be spaced to be apart from the lower blocking layer
72. During the partial removal of the upper blocking layer 172, a
lowermost layer of the plurality of upper insulating layers 161, an
uppermost layer of the plurality of lower insulating layers 61, and
an upper region of the lower blocking layer 72, which are adjacent
to the interface S1, may be partially removed to form the partial
extension portion 171EH. A lateral width of the partial extension
portion 171EH may be greater than a lateral width of the upper
channel hole 171 adjacent to the partial extension portion 171EH.
The lateral width of the partial extension portion 171EH may be
greater than a lateral width of the lower channel hole 71 adjacent
to the partial extension portion 171EH. The partial extension
portion 171EH and the upper blocking layer 172 may be advantageous
for uniformly and continuously forming the inner blocking layer
272, the charge storage layer 82, the tunnel insulating layer 83,
and the channel pattern 86.
[0073] Referring to FIGS. 3 and 39, a plurality of pads 88 may be
formed inside the plurality of upper channel holes 171. A first
interlayer insulating layer 89 may be formed on the plurality of
pads 88 and the preliminary upper stack structure 160T. An
isolation trench 91 may be formed through the first interlayer
insulating layer 89, the preliminary upper stack structure 160T,
the preliminary lower stack structure 60T, the support 50, and the
mold layer 29 and expose the buried conductive layer 25. The mold
layer 29 may be removed to form a replacement conductive line 93.
An impurity region 94 may be formed in the buried conductive layer
25 exposed at a bottom surface of the isolation trench 91. The
plurality of lower sacrificial layers 62 and the plurality of upper
sacrificial layers 162 may be removed, and a plurality of lower
conductive layers 95 and a plurality of upper conductive layers 195
may be formed. Insulating spacers 97 may be formed on sidewalls of
the isolation trench 91. A trench buried layer 98 may be formed to
fill the inside of the isolation trench 91 and be in contact with
the impurity region 94.
[0074] Each of the plurality of pads 88 may be in direct contact
with the channel pattern 86. The plurality of pads 88 may include a
semiconductor layer, such as poly-Si. For example, the plurality of
pads 88 may include an N-type poly-Si layer. In an embodiment, each
of the plurality of pads 88 may serve as a drain region. In an
embodiment, the plurality of pads 88 may include a conductive
layer, such as a metal silicide, a metal, a metal nitride, a metal
oxide, or a combination thereof. The information storage pattern
85, the channel pattern 86, the core pattern 87, and the pad 88 may
constitute a channel structure 70.
[0075] The replacement conductive line 93 may be formed through
side surfaces of the information storage pattern 85 and may be in
contact with the channel pattern 86. The replacement conductive
line 93 may be in direct contact with side surfaces of the channel
pattern 86. The replacement conductive line 93 may include a
conductive material, such as N-type or P-type poly-Si. In an
embodiment, the replacement conductive line 93 may include a metal,
a metal silicide, a metal nitride, a metal oxide, or a combination
thereof. The impurity region 94 may include N-type impurities.
[0076] The plurality of lower conductive layers 95 and the
plurality of upper conductive layers 195 may include a conductive
layer, such as a metal, a metal silicide, a metal nitride, a metal
oxide, poly-Si, conductive carbon, or a combination thereof. The
plurality of lower insulating layers 61 and the plurality of lower
conductive layers 95 that are alternately and repetitively stacked
may constitute a lower stack structure 60. The plurality of upper
insulating layers 161 and the plurality of upper conductive layers
195 that are alternately and repetitively stacked may constitute an
upper stack structure 160. The plurality of lower conductive layers
95 and the plurality of upper conductive layers 195 may include a
metal, a metal silicide, a metal nitride, a metal oxide, poly-Si,
conductive carbon, or a combination thereof.
[0077] The insulating spacers 97 may include silicon oxide, silicon
nitride, silicon oxynitride, a low-k dielectric material, a high-k
dielectric material, or a combination thereof. The trench buried
layer 98 may include a conductive layer, such as a metal, a metal
silicide, a metal nitride, a metal oxide, poly-Si, conductive
carbon, or a combination thereof. In an embodiment, the trench
buried layer 98 may include an insulating layer, such as silicon
oxide, silicon nitride, silicon oxynitride, a low-k dielectric
material, a high-k dielectric material, or a combination
thereof.
[0078] Referring back to FIGS. 1 and 3, a second interlayer
insulating layer 102 may be formed on the first interlayer
insulating layer 89. A plurality of sub-bit plugs 103 may be formed
through the second interlayer insulating layer 102 and the first
interlayer insulating layer 89 and may be in contact with the
plurality of pads 88. A third interlayer insulating layer 104 may
be formed on the second interlayer insulating layer 102. A
plurality of sub-bit lines 105 may be formed in the third
interlayer insulating layer 104 and may be in contact with the
plurality of sub-bit plugs 103. A fourth interlayer insulating
layer 106 may be formed on the third interlayer insulating layer
104. A bit plug 107 may be formed through the fourth interlayer
insulating layer 106 and may be in contact with the plurality of
sub-bit lines 105. A bit line 109 may be formed on the fourth
interlayer insulating layer 106 and may be in contact with the bit
plug 107.
[0079] The first interlayer insulating layer 89, the second
interlayer insulating layer 102, the third interlayer insulating
layer 104, and the fourth interlayer insulating layer 106 may
include an insulating layer, such as silicon oxide, silicon
nitride, silicon oxynitride, a low-k dielectric material, or a
combination thereof. The plurality of sub-bit plugs 103, the
plurality of sub-bit lines 105, the plurality of bit plugs 107, and
the bit line 109 may include a conductive layer, such as a metal, a
metal silicide, a metal nitride, a metal oxide, poly-Si, conductive
carbon, or a combination thereof.
[0080] According to the example embodiments of the inventive
concept, a plurality of channel holes can be formed through a lower
stack structure and an upper stack structure. Each of the plurality
of channel holes can include a lower channel hole, an upper channel
hole, and a partial extension portion configured to communicate
between the lower channel hole and the upper channel hole. A
channel structure having a channel pattern can be disposed inside
the channel hole. The channel pattern can be uniformly and
continuously formed due to the partial extension portion. A
semiconductor device having excellent electrical properties can be
implemented.
[0081] While embodiments of inventive concepts have been described
with reference to the accompanying drawings, it should be
understood by those skilled in the art that various modifications
may be made without departing from the scope of inventive concepts
and without changing features thereof. Therefore, the
above-described embodiments should be considered in a descriptive
sense only and not for purposes of limitation.
* * * * *